I have a couple of the cheap Eelink TK319L units. 1 in the Patrol and the other in my wife's car. I use the $5 Aldi sims with the 365 days expiry.
I have geo-fences set for both. You can send it a message to activate something. It just connects a wire to earth so anything could be activated via a relay such as a fuel cutoff but it won't work above 20 km/h.
You can query where it is with a phone/tablet app or send a SMS and get GPS coordinates in reply. You can also use the app to query where it went on any given date and it replays the route that was taken.
It has a small built in battery that sends a message if main power to it is cut.